Using dogs as a valid model, we compared plasma concentrations of BPA over a 24-hr period after intravenous, orogastric, and sublingual administration in order to establish the absolute ...bioavailability of BPA administered sublingually and to compare it with oral bioavailability.
Our findings demonstrate that BPA can be efficiently and very rapidly absorbed through the oral mucosa after sublingual exposure. This efficient systemic entry route of BPA may lead to far higher BPA internal exposures than known for BPA absorption from the gastrointestinal tract.
Bisphenol A (BPA) risk assessment is currently hindered by the rejection of reported higher-than-expected plasma BPA concentrations in humans after oral ingestion. These are deemed incompatible with the almost complete hepatic first-pass metabolism of BPA into its inactive glucurono-conjugated form, BPA glucuronide (BPAG).
Six dogs were sublingually administered BPA at 0.05 mg/kg and 5 mg/kg. We compared the time course of plasma BPA concentrations with that obtained in the same dogs after intravenous administration of the same BPA doses and after a 20-mg/kg BPA dose administrated by orogastric gavage.
The data indicated that the systemic bioavailability of BPA deposited sublingually was high (70-90%) and that BPA transmucosal absorption from the oral cavity led to much higher BPA internal exposure than obtained for BPA absorption from the gastrointestinal tract. The concentration ratio of BPAG to BPA in plasma was approximately 100-fold lower following sublingual administration than after orogastric dosing, distinguishing the two pathways of absorption.
The mouse monoclonal antibody (mAb) Po66 has been shown in previous work to be localized in nude mice xenografts of human lung tumours when injected intravenously Dazord L et al. (1987) Cancer ...Immunol Immunother 24: 263-268 and to be suitable for the scintigraphic detection of lung cancers in patients Dazord L, et al. (1987) in Klapdor (ed) New tumour markers and their monoclonal antibodies. Georg Thieme, Stuttgart, New York, pp 444-450. The nature of the antigen recognized by Po66 has been investigated in the present work and comparisons are made with antigens recognized by other mAbs prepared in the laboratory. These mAbs were raised either against lung squamous cell carcinoma (mAbs Po43, Po60), or against a bronchio-alveolar carcinoma (mAbs BAM33, BAM45, BAM54 and BAM69). Radioiodinated purified Po66 did not compete for cell binding with any other mAb. All Po and BAM mAbs reacted with tumour cells both cultured in vitro and grown in vivo. They recognized cytoplasmic antigens as judged by immunofluorescence examination of fixed cells or by immunoperoxidase staining of cancer tissues, but could never be visualized by immunofluorescence on the surface membrane of culture cells. The mAbs of the BAM series reacted with vimentin as demonstrated by immunofluorescence staining, showing alterations in the aspect of the filaments under the effect of colchicine. Radiolabelled mAbs Po43, BAM33 and BAM45 bound to partially purified cytoplasmic cytoskeleton components. In contrast, Po66 was never seen associated with intermediary filaments. The sensitivity to enzyme digestion of the antigen associated with Po66 was studied in comparison with those associated with Po43, BAM33 and BAM45. All antigens were sensitive to protease digestion while only the Po66-identified antigen was sensitive to periodate, neuraminidase and alpha-fucosidase. Thus, mAb Po66 identified an antigen of 47 kDa (as determined before) present in the cytoplasm but not related to the cytoskeleton, not detected on the cell surface and glycoprotein in nature.
Since the beginning of 2000s, imports of frozen pieces of chicken from the European Union or America have considerably increased in several African and Caribbean developing countries, competing with ...local chicken meat. This evolution has contributed to a complete transformation of urban consumption habits as regards poultry meat. Investigations have been done in 2005 in Yaoundé (Cameroon) and in 2006 at Port-au-Prince (Haiti) applied to 180 urban households in each country, showing that imported frozen pieces of chicken have widely substituted for the local chicken which has already quite disappeared in Port-au-Prince, but is still appreciated by Yaoundé consumers. This article aims to assess the impacts, on such an evolution of i) socio-economic features of consumers and ii) the impact of chicken consumption habits, for what imported versus domestic chicken may be more or less adapted. In order to take into account numerous qualitative variables, econometric regressions are using synthetic continue variables built on multiple correspondence analysis of qualitative variables. Results differ from Port-au-Prince to Yaoundé.
Depuis le début des années 2000, les importations de volaille congelée en provenance d’Europe et d’Amérique se sont considérablement développées dans plusieurs pays en développement d’Afrique et des Caraïbe, concurrençant les productions locales de poulet. Cette évolution s’est traduite par une mutation des habitudes de consommation de viande de poulet en milieu urbain. Des enquêtes, menées en 2005 à Yaoundé (Cameroun) puis en 2006 à Port au Prince (Haïti), auprès de 180 ménages urbains chaque pays, ont montré que les découpes importées de poulet congelé se sont largement substituées au poulet local. Ce dernier a presque disparu à Port-au-Prince, mais reste apprécié des consommateurs à Yaoundé. Cet article vise à mettre en évidence les déterminants de cette évolution en évaluant d’une part le rôle joué par la situation socio-économiques des ménages urbains, et d’autre part le rôle joué par les modes de consommation de poulet impact, auxquels les différents produits sur les marchés sont plus ou moins bien adaptés. De façon à prendre en compte les très nombreuses variables qualitatives, les régressions économétriques utilisent des variables synthétiques continues construites sur la base d’analyse des correspondances multiples. Les résultats obtenus diffèrent sensiblement d’une zone enquêtée à l’autre.
Using pharmacological and molecular approaches to investigate
β-adrenoceptor (
β-AR) subtype expression in adult rat diaphragm, we found that adenylyl cyclase (AC) was potently stimulated by the
β
...2-AR-selective agonist fenoterol, weakly stimulated by the
β
1-AR-selective agonist prenalterol and unaffected by the
β
3-AR agonist CGP12177. AC activity in response to a submaximal isoproterenol concentration was potently inhibited by the
β
2-AR-selective antagonist ICI118551, whereas the
β
1-AR-selective antagonist CGP20712A was effective only in very high concentrations. (−)-
125I-cyanopindolol (
125I-CYP) saturation binding experiments indicated a single affinity component (dissociation constant (
K
d)=22±2 pM) for
β-AR sites (maximal
β-AR density (
B
max)=14±2 fmol/mg). Eadie–Hofstee analysis of
125I-CYP displacement curves by
β
1-,
β
2- or
β
3-AR-selective ligands allowed to characterise a homogenous population of
β
2-AR sites. Finally, reverse transcriptase–polymerase chain reaction analysis of
β-AR subtype mRNAs identified
β
2-AR transcripts but no
β
1- and
β
3-AR mRNAs. Our results demonstrate that
β
2-AR is the only
β-AR subtype expressed in the diaphragm.
The putative thyroid-disrupting properties of bisphenol A (BPA) highlight the need for an evaluation of fetal exposure and its consequence on the mother/newborn thyroid functions in models relevant ...to human. The goals of this study were to characterize in sheep a relevant model for human pregnancy and thyroid physiology, the internal exposures of the fetuses and their mothers to BPA and its main metabolite BPA-glucuronide (Gluc), and to determine to what extent it might be associated with thyroid disruption. Ewes were treated with BPA 5 mg/(kg . d) sc or vehicle from d 28 until the end of pregnancy. Unconjugated BPA did not appear to accumulate in pregnant ewes, and its concentration was similar in the newborns and their mothers (0.13 +/- 0.02 and 0.18 +/- 0.03 nmol/ml in cord and maternal blood, respectively). In amniotic fluid and cord blood, BPA-Gluc concentrations were about 1300-fold higher than those of BPA. Total T-4 concentrations were decreased in BPA-treated pregnant ewes and in the cord and the jugular blood of their newborns (30% decrease). A similar difference was observed for free T-4 plasma concentrations in the jugular blood of the newborns. Our results show in a long-gestation species with a similar regulatory scheme of thyroid function as humans that BPA in utero exposure can be associated with hypothyroidism in the newborns. If such an effect were to be confirmed for a more relevant exposure scheme to BPA, this would constitute a major issue for BPA risk assessment.
Hybridoma AP-282 was produced by fusing mouse plasmacytoma cells with splenocytes of mice immunized against purified human polymorphonuclear cells. The secreted monoclonal antibody (MAb), AP-282, a ...mouse IgG1, was found to react strongly with all neutrophilic granulocytes, their bone marrow precursors, weakly with blood monocytes and not with eosinophils. The antigen was resistant to formalin fixation but was destroyed by exposure to fixatives containing acetic acid. Using the APAAP technique, antibody AP-282 strongly labelled neutrophils on sections of frozen cut or paraffin embedded tissues. No staining was seen of non hematopoietic tissues. AP-282 recognized an internal antigen associated to cytoplasmic granules. Chemical investigations on dot blots of whole or of purified cellular extracts indicated that the antigen idenfied by MAb AP-282 was different from those recognized by usual antigranulocyte antibodies, i.e. myeloperoxidase, elastase, cathepsin G and lactoferrin. Thus, antibody AP-282 constitutes a new cytoplasmic marker of neutrophils.
Since the beginning of 2000s, imports of frozen pieces of chicken from the European Union or Brazil have considerably increased in several African and Caribbean developing countries, competing with ...local chicken meat. Obviously, imported chicken has replaced domestic one in households’ consumption. The level of substitution between imported chicken and the several domestic chicken types is not specifically known. In order to focus on this point, investigations have been done in 2005 in Yaoundé (Cameroon) and in 2006 in Port-au-Prince (Haiti). Because of a lack of available statistical data, we surveyed 180 urban households in each country, showing that imported frozen pieces of chicken have widely substituted for the local chicken which has already quite disappeared in Port-au-Prince, but is still appreciated by Yaoundé consumers. This article aims to assess the impacts, on such an evolution of i) socio-economic features of consumers and ii) of chicken consumption habits of households. Without data on income, and to deal with a large number of qualitative variables, we implemented multiple correspondence analyses to build asset indexes usable in our econometric regressions.
Depuis le début des années 2000, les importations de volaille congelée en provenance d’Europe et d’Amérique se sont considérablement développées dans plusieurs pays en développement d’Afrique et des Caraïbes, concurrençant les productions locales de poulet. En revanche, le degré de substitution, dans la consommation des ménages, entre le poulet importé et les différents types de poulet produits localement, est mal connu. De façon à préciser cet aspect, et du fait du manque de données statistiques à ce niveau de précision, des enquêtes ont été menées, en 2005 à Yaoundé (Cameroun) puis en 2006 à Port au Prince (Haïti), auprès de 180 ménages urbains dans chaque pays. Les résultats montrent que les découpes importées de poulet congelé se sont effectivement largement substituées au poulet local : ce dernier a presque disparu à Port-au-Prince, mais reste apprécié des consommateurs à Yaoundé. Cet article approfondit la question des déterminants de cette évolution en évaluant le rôle joué d’une part par la situation socio-économique des ménages urbains, et d’autre part par les modes de consommation de poulet des ménages. De façon à prendre en compte les très nombreuses variables qualitatives, les régressions économétriques utilisent des variables synthétiques continues construites sur la base d’analyse des correspondances multiples.
